• N. Chauvin, O. Delferrière, R.D. Duperrier, R. Gobin, P.A.P. Nghiem, D. Uriot
  CEA, Gif-sur-Yvette

The purpose of the IFMIF-EVEDA (International Fusion Materials Irradiation Facility-Engineering Validation and Engineering Design Activities) demonstrator is to accelerate a 125 mA cw deuteron beam up to 9 MeV. Therefore, the project requires that the ion source and the low energy beam transport (LEBT) line deliver a 140 mA cw deuteron beam with an energy of 100 keV and an emittance of 0.25 π .mm.mrad (rms normalized) at the entrance of the RFQ. The deuteron beam is extracted from a 2.45 GHz ECR source based on the SILHI design*. A LEBT with a two solenoids focusing system is foreseen to transport and adapt the beam for the RFQ injection. In order to validate the LEBT design, intensive beam dynamics simulations have been carried out using a parallel implementation of a particle-in-cell 3D code which takes into account the space charge compensation of the beam induced by the ionisation of the residual gas. The simulations results (in particular from the emittance growth point of view) performed under several conditions of gas species or gas pressure in the beam line are presented.

*R. Gobin et al, Rev. Sci. Instrum. 79, 02B303 (2008).

• P.A.P. Nghiem, N. Chauvin, O. Delferrière, R.D. Duperrier, A. Mosnier, D. Uriot
  CEA, Gif-sur-Yvette
• M. Comunian
  INFN/LNL, Legnaro, Padova
• C. Oliver
  CIEMAT, Madrid

One major subsystem of IFMIF (International Fusion Materials Irradiation Facility) is its accelerator facility, consisting of two 175 MHz CW accelerators, each accelerating a deuteron beam of 125 mA to the energy of 40 MeV. This high power beam, 10 MW, induces challenging issues that lead to plan a first phase called EVEDA (Engineering Validation and Engineering Design Activity), where only the portion up to 9 MeV of one accelerator will be constructed and tested. For these accelerators, the Parameter Design phase is about to be completed. This paper presents the status of these studies. Due to the very high beam intensity, particular efforts have been dedicated to minimise the space charge effect that can strongly increase the beam size via the halo, and the losses that can prohibit the requested hand-on maintenance. For that, Beam Dynamics simulations have been performed with 10⁶ macro-particles, and a great vigilance has been granted to the emittance growth and the particles on the beam edge. Several possible solutions are presented, for which advantages and drawbacks to fulfil the specifications are discussed.